This application claims the priority of Korean Patent Application No. 2002-3868, filed on Jan. 23, 2002, which is incorporated herein in its entirety by reference.
1. Field of the Invention
The present invention relates to an emotion recognition system and method thereof, and more particularly, to an emotion recognition system and method thereof which enables perception of a user's emotional state by monitoring his or her physiological signals.
2. Description of the Related Art
An emotion refers to a mental state which is associated with certain physiological activity and is caused by internal or external environmental stimulus. Emotional states are broadly classified into positive emotions and negative emotions. The former includes happiness, contentment (pleasure), tranquility, elation, etc., and the latter includes sadness, discontent (displeasure), anger, surprise, fear, depression, etc. Besides these emotions, more diverse classification of emotions is possible. Herein, an example of internal stimulus includes an old memory or a subjective emotional stimulus, and an example of external stimulus includes stress or the relief of stress due to various environmental factors except for voluntary stimulus of an emotional subject.
Theories for defining emotions include the James-Lange theory in which an appropriate emotion is experienced by recognizing physiological changes of an autonomic nervous system upon the input of an external environmental stimulus to a human body, and the Cannon-Bard theory in which a physiological reaction to an external environmental stimulus and a psychological or emotional experience occur simultaneously. The difference between these two theories is that the former is based on a peripheral organ in the human nervous system being the origin of occurrence of an emotion, while the latter is based on the human brain being the origin of occurrence of an emotion.
As mentioned above, a change of an emotional state due to an internal or external environmental stimulus involves a change of physiological characteristics of a human body caused by an adjustment of an autonomic nervous system. Accordingly, a change of an emotional state can be recognized by measuring physiological signals reflecting physiological changes such as changes in heart beat, Electromyogram (EMG), electrodemal conductivity, body temperature, etc. An appropriate physiological signal sensor can measure these physiological signals.
Methods of recognizing an emotion based on a physiological signal acquired through a physiological signal sensor have already been disclosed in several associated patents. For example, a device for analyzing an emotional state caused by a stimulus from an external environmental stimulus means such as TV, etc., is disclosed in U.S. Pat. No. 5,676,138 to Zawilinski, issued October 1997 and entitled “EMOTIONAL RESPONSE ANALYZER SYSTEM WITH MULTIMEDIA DISPLAY”. However, a problem with this method is that it shows only a limited amount of experimental data and a result, and an emotional state is identified through the use of a z-score, thereby resulting in a decreased accuracy of the emotional response analyzer.